Some commonly used excavators have an excavation bucket mounted at the end of a boom. The excavation bucket has an open front side, while a door on its rear side. The lower edge of the open front side has teeth for excavating.
The excavator first scoops up dirt with the rear-side door of the bucket closed. The boom then moves so that the bucket is above a dropping zone (e.g., a truck), at which point the rear-side door of the bucket faces downward. The door is then opened, for instance by the release of a latch. The door opens under its weight and the weight of the dirt in the bucket, whereby the dirt is dumped. To close the door, the latch grabs the door when the excavation bucket is moved to scoop up another load of dirt.
A common problem with such excavator configurations is that the door of the excavation bucket is subjected to violent impact. This may lead to the premature wear of the doors, and costly repairs and downtime. Accordingly, snubbers also known as brakes, dampers, mechanical snubbers, etc, are used to reduce oscillation of the door, therefore reducing the impact at closing of the door.
Hydraulic snubbers feature a pair of chambers separated by a wiper, with the wiper moving with the excavation door to change the volume of the chambers. A fluid (e.g., hydraulic oil) moves between chambers, and this flow is controlled to oppose torque to the movement of the door. However, the various components of such hydraulic snubbers are subjected to high pressures and wear, in addition to being exposed to the elements (e.g., temperature variations), which may affect the performance and durability of the snubbers.